Abstract: Objective Detect the immunogenicity of conservative neutralizing epitope from human papillomavirus type 31 (HPV31) minor capsid protein L2, and analyze the neutralizing antibody spectrum of its immune sera. Methods Synthesize HPV31 L2 aa.17-40 peptide and conjugate with KLH by EDC. Immunize New Zealand White rabbits with HPV31 L2-KLH and Freud’s Adjuvant. Analyze the neutralizing antibody titers of immune sera against HPVs from α4,α7,α9,α10 and β1 species by pseudovirus neutralization assay. Results In rabbits, HPV31 L2-KLH induced broad-spectrum neutralizing antibodies against at least 17 types of HPV, among which the neutralizing antibody titers against HPV31 are the highest, followed by that of HPV5/45/57. Conclusions In this study, we observed the broad-spectrum neutralizing activities of the immune sera of HPV31 L2 conservative neutralizing epitope for the first time. The results lay the foundation of the development of broad-spectrum HPV vaccines based on HPV31 L2 neutralizing epitope.

Key words: human papillomavirus type 31, L2 conservative neutralizing epitope, broad-spectrum neutralizing antibody